Machining center with automatic tool changer

ABSTRACT

A machining center type machine tool which is a four-axis, horizontal spindle machining center with a carousel-type automatic tool changer and which is adapted to be controlled by a computer numerical control system. The machining center can perform a variety of machining operations, such as milling, contouring, drilling, tapping and boring, in both roughing and finishing applications. A rotary work table is operatively carried on two movable, perpendicularly disposed slide members to provide movement of the work table along both &#34;X&#34; and &#34;Z&#34; axes. A horizontal tool spindle slide assembly is slidably mounted on a &#34;Y&#34; axis on a twin column assembly. A rotary, carousel-type combination tool storage and tool changer, holding twenty-four tools, is rotatably mounted on a horizontal axis that is aligned and parallel with the axis of the horizontal tool spindle. The rotary carousel functions to automatically load and unload tools directly into the tool spindle at a tool exchange location. The tool spindle extracts the tools from the carousel, and inserts the tools back into the carousel after a cutting operation. The machining center includes a manually operated optional pallet changer for automatically loading a pallet carrying a new workpiece onto the work table, and unloading the pallet with a finished workpiece from the work table. The tool spindle is provided with automatic mechanical spindle positioning for each spindle stop.

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates to machining center type machine tools, and moreparticularly to four-axis, horizontal spindle machining centers capableof performing various machining operations including milling,contouring, boring, drilling and tapping, in both roughing and precisionfinishing applications, and which are provided with automatic toolchanger means and controlled by numerical control means.

2. Description of the Prior Art

It is known in the machine tool art to provide machining center typemachine tools having rotatable machine tool spindles that are capable ofbeing stopped at a predetermined angular position, and which areprovided with automatic tool changer means for transferring tools in apredetermined sequence directly between a tool storage means and thetool spindle, to provide the tool spindle with a predetermined sequenceof tools, for carrying out a desired sequence of operations. Adisadvantage of the prior art machining centers is that one or more toolchanger means must be employed for transferring tools between the toolstorage means and the tool spindle, which action increases the tooltransfer time. Another disadvantage of the prior art machining centersis that the tool storage means is disposed in a position whereby theoperator does not have full visibility of the tools when they are in thestorage means, and the storage means is not accessible to the operatorfor manual changing of the tools between tool change cycles while themachining center is running. A further disadvantage of the prior artmachining centers is that they are complex, and constructed and arrangedwhereby heat from the lube oil and heat generated by the running of themachine is retained in the machine structure, which adversely affectsthe accuracy of the machining operations carried out by the machiningcenter. The prior art machining centers employ the use of hydrauliccylinders for tool changing and other machine functions which produceadverse heat and noise.

SUMMARY OF THE INVENTION

In accordance with the present invention, the illustrative embodiment ofthe invention comprises a horizontal spindle, four-axis machining centerwhich is capable of performing a variety of machining operationsincluding milling, contouring, boring, drilling and tapping, in bothroughing and precision finishing applications, and adapted to becontrolled by a computer numerical control means. The automatic toolchanger means also functions as a tool storage means, and it comprises abi-directional, random-select tool carousel which is rotatably mountedon a horizontal axis above the horizontal tool spindle to permit therotatable carousel to directly load and unload a selected sequence oftools into and out of the tool spindle. The tool spindle and thecombination tool storage and tool changer carousel function together toeffect tool transfer operations without the need for any intermediatetool changer means. The tool spindle functions to withdraw a selectedtool for a cutting operation from the tool carousel and to replace thetool after the cutting operation back into its previous position in thetool carousel. The tool carousel inserts a selected tool into the toolspindle for a cutting operation and removes the tool from the toolspindle after the cutting operation. The tool spindle is automaticallypositioned in a predetermined angular position at each spindle stop by amechanical means which also releases the tool carried in the spindle. Upto twenty-four tools can be stored in the rotary, high speed carouseltool changer which changes tools in four seconds. The tool carousel isprovided with an up-and-down counter for controlling the operation ofthe carousel to stop the carousel with the required tool in the toolexchange location.

The machining center includes a work table which is rotatably mountedabout a vertical axis on a work table slide assembly which is adapted tobe moved on a saddle slide assembly toward and away from the toolspindle, as viewed from the front of the machine, along the "Z" ortransverse axis. The tool spindle is movable upwardly and downwardly ona twin column assembly on the "Y" or vertical axis. The saddle slideassembly is slidably mounted on an "X" axis base for movement left orright, as viewed from the front of the machining center, along the "X"or longitudinal axis.

All of the machine functions are electro-mechanical. High responsedirect current servo motors are employed for driving preloaded precisionball screws for moving the "X", "Y" and "Z" axes slides and for rotatingthe rotary work table, and for driving the tool spindle through atwospeed gear transmission. All hydraulic equipment normally associatedwith multi-access machines has been eliminated, and only one smallpneumatic cylinder is employed, whereby the machining center operates ata low noise level heretofore not achievable by the aforecited prior artmachining centers. The machining center employs various mechanicalapparatuses which are designed so that the action of one member causes adefinite positive action of another, whereby almost all sequencing,orienting and positioning is positive, sure and safe.

The machining center of the present invention includes an optionalpallet changer to maximize machine utilization. While one part is beingmachined, another part can be loaded on the pallet changer. Whenmachining of the first part is complete, manual activation of the shortpallet change cycle places the second part into a work station on themachine. The pallet changer includes a rotary design which reduces floorspace requirements, and keeps the loading operation close to theoperator's normal work station at all times.

Other objects, features and advantages of this invention will beapparent from the following detailed description, appended claims, andthe accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a front elevation perspective view of a machining center withan automatic tool changer made in accordance with the principles of thepresent invention, and provided with an optional pallet changer.

FIG. 2 is a reduced, front elevation view of the machining centerillustrated in FIG. 1.

FIG. 3 is a top plan view of the machining center illustrated in FIG. 2,taken along the line 3--3 thereof, and looking in the direction of thearrows.

FIG. 4 is a right side, elevation view of the machining centerillustrated in FIG. 3, taken along the line 4--4 thereof, and looking inthe direction of the arrows.

FIG. 5 is a rear elevation view of the machining center illustrated inFIG. 4, taken along the line 5--5 thereof, and looking in the directionof the arrows.

FIG. 6 is a fragmentary, enlarged elevation section view of themachining center structure illustrated in FIG. 4, taken along the line6--6 thereof, and looking in the direction of the arrows.

FIG. 7 is an enlarged, left side elevation view of the machining centerstructure illustrated in FIG. 3, with parts removed, taken along theline 7--7 thereof, and looking in the direction of the arrows.

FIG. 8 is an elevation view of the machining center structureillustrated in FIG. 7, with parts broken away and parts in section,taken along the line 8--8 thereof, and looking in the direction of thearrows.

FIG. 9 is a top plan view of the machining center structure illustratedin FIG. 8, with parts removed, parts broken away, and parts in section,take along the line 9--9 thereof, and looking in the direction of thearrows.

FIG. 10 is an enlarged, fragmentary, front elevation view of the spindleassembly employed in the machining center structure illustrated in FIG.7, taken along the line 10--10 thereof, and looking in the direction ofthe arrows.

FIG. 11 is a horizontal view of the machining center structureillustrated in FIG. 7, with parts removed and parts broken away, takenalong the line 11--11 thereof but turned 90°, and looking in thedirection of the arrows.

FIG. 12 is a rear elevation view of the spindle assembly employed in themachining center shown in FIG. 11, taken along the line 12--12 thereof,and looking in the direction of the arrows.

FIG. 13 is a fragmentary, enlarged elevation section view of the spindleassembly structure illustrated in FIG. 12, taken along the line 13--13thereof, and looking in the direction of the arrows.

FIG. 14 is a fragmentary, enlarged elevation section view of the spindleassembly illustrated in FIG. 12, taken along the line 14--14 thereof,and looking in the direction of the arrows.

FIG. 14A is a fragmentary, enlarged elevation section view, similar toFIG. 14, of the spindle assembly structure employed in the machiningcenter of the present invention.

FIG. 15 is a fragmentary, elevation view of the spindle assemblystructure illustrated in FIG. 14, taken along the line 15--15 thereof,and looking in the direction of the arrows.

FIG. 16 is a side elevation view of the collet employed in the spindleassembly shown in FIG. 14A.

FIG. 17 is a right side elevation view of the collet illustrated in FIG.16, taken along the line 17--17 thereof, and looking in the direction ofthe arrows.

FIG. 18 is a fragmentary, enlarged elevation section view of the colletillustrated in FIG. 17, taken along the line 18--18 thereof, and lookingin the direction of the arrows.

FIG. 19 is a fragmentary, elevation section view of the spindle assemblyillustrated in FIG. 14, taken along the line 19--19 thereof, looking inthe direction of the arrows, and showing the clutch employed in thespindle assembly.

FIG. 20 is a side elevation view of the clutch shown in FIG. 19, takenalong the line 20--20 thereof, and looking in the direction of thearrows.

FIG. 21 is a fragmentary, enlarged, front elevation view of the carouseltype tool changer illustrated in FIG. 7, taken along the line 21--21thereof, and looking in the direction of the arrows.

FIG. 22 is a top plan view of the machining center structure illustratedin FIG. 21, taken along the line 22--22 thereof partially shown insection therethrough, and looking in the direction of the arrows.

FIG. 23 is an enlarged, front elevation view of the base, saddle andtable assembly, as seen in FIG. 2, but without the optional palletchanger.

FIG. 24 is a top plan view of the machining center structure shown inFIG. 23, taken along the line 24--24 thereof, and looking in thedirection of the arrows.

FIG. 25 is a left side view of the machining center structureillustrated in FIG. 24, taken along the line 25--25 thereof, and lookingin the direction of the arrows.

FIG. 26 is a fragmentary, enlarged, front elevation view of the saddleslide assembly illustrated in FIG. 24, taken along the line 26--26thereof, and looking in the direction of the arrows.

FIG. 27 is a top plan view of the saddle slide assembly illustrated inFIG. 26, taken along the line 27--27 thereof, and with the tablestructure removed.

FIG. 28 is a left side elevation view of the saddle slide assemblyillustrated in FIG. 27, taken along the line 28--28 thereof, and lookingin the direction of the arrows.

FIG. 29 is a right side elevation view of the saddle slide assemblyillustrated in FIG. 27, taken along the line 29--29 thereof, and lookingin the direction of the arrows.

FIG. 30 is an enlarged, top view of the work table assembly illustratedin FIG. 23, taken along the line 30--30 thereof, and looking in thedirection of the arrows.

FIG. 31 is an enlarged, elevation view of the work table structureillustrated in FIG. 30, taken in the direction of the arrow marked "31"and with the table drive motor removed.

FIG. 32 is an enlarged, fragmentary, horizontal section view of the worktable structure illustrated in FIG. 31, taken along the line 32--32thereof, and looking in the direction of the arrows.

FIG. 33 is an enlarged, front elevation view of the work table structureillustrated in FIG. 30, shown partly in front elevation, and partly insection taken along the line 33--33 of FIG. 30 and looking in thedirection of the arrows.

FIG. 34 is a right side elevation view of the work table structureillustrated in FIG. 33, taken along the line 34--34 thereof, and lookingin the direction of the arrows.

FIG. 35 is a fragmentary, elevation view of the work table assemblyillustrated in FIG. 33, taken along the line 35--35 thereof, and lookingin the direction of the arrows.

FIG. 36 is a bottom view of the work table assembly illustrated in FIG.33, taken along the line 36--36 thereof, with the saddle slide assemblyremoved, and looking in the direction of the arrows.

FIG. 37 is a rear end elevation view of the work table assemblyillustrated in FIG. 36, taken along the line 37--37 thereof, and lookingin the direction of the arrows.

FIG. 38 is a front end elevation view of the work table assemblyillustrated in FIG. 36, taken along the line 38--38 thereof, and lookingin the direction of the arrows.

FIG. 39 is a fragmentary, enlarged, elevation view of the machiningcenter structure illustrated in FIG. 3, taken substantially along theline 39--39 thereof, and looking in the direction of the arrows, andillustrating a work table provided with an optional pallet changerassembly structure.

FIG. 40 is a top plan view of the machining center structure illustratedin FIG. 39, taken along the line 40--40 thereof, and looking in thedirection of the arrows.

FIG. 41 is a right side elevation view of the machining center structureillustrated in FIG. 39, taken along the line 41--41 thereof, and lookingin the direction of the arrows.

FIG. 42 is a right side elevation view of the structure illustrated inFIG. 41, taken along the line 42--42 thereof, and looking in thedirection of the arrows.

FIG. 43 is a front elevation view of the pallet changer assemblystructure illustrated in FIG. 3, taken along the line 43--43 thereof,and looking in the direction of the arrows.

FIG. 44 is a left side elevation view of the pallet changer assemblystructure illustrated in FIG. 43, taken along the line 44--44 thereof,and looking in the direction of the arrows.

FIG. 45 is a fragmentary, enlarged, right side elevation view of thepallet changer assembly structure illustrated in FIG. 44, taken alongthe line 45--45 thereof, and looking in the direction of the arrows.

FIG. 46 is a fragmentary, top view, with parts broken away, of thepallet changer assembly structure illustrated in FIG. 45, taken alongthe line 46--46 thereof, and looking in the direction of the arrows.

FIG. 47 is a fragmentary, enlarged, elevation section view of thestructure illustrated in FIG. 45, taken along the line 47--47 thereof,and looking in the direction of the arrows.

FIG. 48 is a perspective, schematic view of the carousel type toolchanger and machine tool spindle, and showing the relative movementsthereof during a tool changing operation.

FIG. 49 is a block diagram of an illustrative electronic circuit forselection of tools from the carousel.

DESCRIPTION OF THE PREFERRED EMBODIMENT General Description

Referring now to the drawings, and in particular to FIG. 1, the numeral10 generally designates an illustrative embodiment of the invention,which comprises a horizontal spindle, four-axis machining center that iscapable of performing a variety of machining operations, includingmilling, contouring, boring, drilling and tapping, in both roughing andprecision finishing applications. The machining center 10 includes atwin column assembly generally indicated by the numeral 11, on which isslidably mounted a tool spindle slide assembly, generally indicated bythe numeral 12, which is mounted for vertical movement along the "Y"axis. The numeral 13 generally designates a rotatable tool storagecarousel means which is operatively mounted on the top of the twincolumn assembly 11 for rotation about a horizontal axis that is invertical alignment with the rotary axis of the tool spindle carried bythe tool spindle slide assembly 12, as more fully described hereinafter.

A base member, generally indicated by the numeral 14, is operativelymounted in front of the twin column assembly 11. The base 14 hasprovided on the upper side thereof an "X" axis or longitudinal axisstructure on which is slidably mounted a saddle slide assembly,generally indicated by the numeral 15. The numeral 16 generallydesignates a work table assembly which is operatively supported on thesaddle slide assembly 15 for movement along the "Z" axis or transverseaxis.

FIGS. 1 through 5 show the machining center 10 provided with an optionalpallet changer apparatus, generally indicated by the numeral 22. Whenthe pallet changer apparatus 22 is employed, a pair of interchangeablepallets 18 and 19 are employed. When the optional pallet changerapparatus 22 is not employed, then the work table assembly 16 isprovided with a work table 17, as shown in FIGS. 33 and 34. As shown inFIG. 1, an operator's control panel, generally indicated by the numeral20, is operatively mounted on one side of the twin column assembly 11,and a second control panel, generally indicated by the numeral 21, isoperatively mounted on the other side of the twin column assembly 11.

Twin Column Assembly

As shown in FIGS. 2, 8 and 9, the twin column assembly 11 includes aleft column, generally indicated by the numeral 25, and a right column,generally indicated by the numeral 26. As shown in FIG. 9, a columnassembly top plate 27 integrally connects the upper ends of the left andright columns 25 and 26, respectively. Each of the columns 25 and 26,respectively. Each of the columns 25 and 26 includes a vertical outerside wall 28, a front wall 29, a rear wall 30, an inner side wall 31,and a transverse inner wall 32. The column assembly top plate 27 isprovided with a plurality of openings 33. As shown in FIGS. 7 and 8, thelower ends of the columns 25 and 26 are connected by integral front andrear housing walls 34 and 35, respectively. The upper ends of thehousing walls 34 and 35 are enclosed by a horizontal housing wall 36(FIG. 7). As shown in FIG. 5, the upper ends of the columns 25 and 26are also connected by front and rear vertical housing wall portions 37.As shown in FIGS. 5, 7 and 8, each of the columns 25 and 26 is providedalong the lower side thereof with an integral, horizontal footing memberor flange 38 through each of which is operatively mounted a pair ofleveling screw jacks 39. The control boards 20 and 21 are operativelyattached to the adjacent column assembly 11, by any suitable means, asby suitable machine screws (not shown). As shown in FIG. 8, each of thecolumns 25 and 26 is provided along the front inner side with alongitudinally extended, and outwardly positioned "Y" or vertical axisways 44 which are integral at their upper ends with a transverseextension plate 45 that extends forwardly from the column top plate 27.

Tool Spindle Slide Assembly

The tool spindle slide assembly 12 is best seen in FIGS. 10, 11, 12, 14and 14A. As shown in FIG. 14, the tool spindle slide assembly 12includes the spindle slide housing, generally indicated by the numeral46, and in which is rotatably mounted a tool spindle, generallyindicated by the numeral 47. The spindle slide housing 46 includes afront wall 49, an integral top wall 50, and an integral bottom wall 51.As shown in FIG. 14A, the spindle slide housing 46 is also provided withan integral, forwardly extended horizontal cylindrical housing portion52 in which is rotatably supported the front end of the tool spindle 47.As shown in FIG. 11, the spindle slide housing 46 is provided with apair of rearwardly extended integral side walls 53 and 54 which areenclosed at the rear ends thereof by a rear end housing wall 55. Asshown in FIG. 12, the rear housing wall 55 is releasably secured inplace by a plurality of suitable machine screws 56.

The spindle slide housing 46 includes a pair of sidewardly extended arms59 and 60, which are adapted to be slidably mounted on the outer facesof the vertical axis ways 44. As shown in FIG. 11, the housing arm 59has secured to the rear side thereof an L-shaped keeper member 63 whichis adapted to be slidably engaged with the outer face and a part of therear face of one of the ways 44. The keeper 63 is secured to the housingarm 59 by any suitable means, as by a pair of machine screws 64. Theother housing arm 60 is also provided with a keeper member 65 which issecured to a rearwardly extended portion of the arm 60 by a machinescrew 66. The keepers 63 and 65 function with the housing arms 59 and 60to provide the vertical axis slide ways 67 and 68. The slide way 67 isprovided with a conventional way wiper 69 which is secured in place bysuitable machine screws 72. The slide way 68 is also provided with asimilar way wiper 73 which is secured in place by suitable machinescrews 74. As shown in FIG. 11, the slide ways 67 and 68 are providedwith suitable lubricant passageways 75 which are each supplied withlubricant through a fitting 76, and a nylon tubing 77. The tubes 77 areconnected to a conventional lubricant meter unit 80 which is connectedby a nylon tubing 81 to a fitting 82 which is mounted on the rear sideof the column assembly 11, as shown in FIG. 7. Fitting 82 is connectedby nylon tubing 83 to a lubricant supply unit 84 that is secured to therear side of the column 25 by means of mounting flange 85 and a machinescrew 86. As shown in FIGS. 14 and 14A, the tool spindle 47 includes anelongated tubular body 87 which is rotatably mounted at its forward endin the tubular housing 52 by a suitable roller thrust bearing, generallyindicated by the numeral 90. As shown in FIG. 14A, the outer race of thebearing 90 is seated against a shoulder 91 formed at the junction pointof the bore 89 in the housing 52, and an enlarged bore 92 in the housing52. The inner race of the bearing means 90 is seated on an enlargeddiameter portion 93 of the tool spindle body 87, and it is held in placeby a slinger plate 94 which is seated against a shoulder formed on theenlarged outer end head 95 of the tool spindle body 87, A retainer ring96 is secured to the outer end of the tubular housing 52 by any suitablemeans, as by suitable socket head screws 97.

A tool drive key 101 is operatively mounted in a recess 100 formed inthe outer face of the spindle body head 95, and it is secured in placeby a suitable socket head screw 102. The drive key 101 seats in thekeyway 99 in the tool chuck 104 for locating and driving purposes. Asshown in FIG. 14A, the bearing means 90 is lubricated by a suitablelubricant admitted through the passage 103 from the interior of thehousing 46.

As shown in FIG. 14A, a conventional tool holder or tool chuck,generally indicated by the numeral 104, is provided with a tapered shank105 that is adapted to be operatively seated in a tapered socket 106formed in the outer end of the tool spindle body 87. The tool chuck 104is provided with a conventional peripheral V-groove 107, on the outerend thereof, for operative engagement with the tool storage carouselmeans 13, as described hereinafter. The tool chuck 104 is illustrativeof the type tool holders which may be employed with the tool spindle 47for carrying various types of tools, as indicated by the numeral 108 inFIG. 1.

As shown in FIG. 14A, the inner end or rear end of the tool spindle body87 is rotatably supported by a suitable bearing means 109 which isoperatively mounted in a bore 110 in the housing rear wall 55. Thebearing 109 is retained against a retaining shoulder 111 at the innerend of the bore 110 by a suitable lock nut 112 which is threadablymounted on the rear end of the tool spindle body 87.

The tool spindle body 87 is provided with a longitudinal axial bore 113in which is longitudinally movable a draw bar means generally indicatedby the numeral 114. The draw bar means 114 includes an elongatedcylindrical body or rod 115, to the front end of which is attached acollet body 116 of a collet type tool holder gripping means. A pluralityof collet fingers 117 are integrally connected to the collet body 116and they are provided on their outer ends with integral cam heads 118.As shown in FIG. 14A, the draw bar means 114 is in the operative or toolholder gripping means position with the collet fingers 117 cammed inwardto bring the cam heads 118 into a gripping engagement with the retentionknob 120 of the illustrated self-locking tool chuck 104. It will be seenthat when the draw bar body 115 is moved to the position shown in FIG.14A, that the collet cam heads 118 are moved rearwardly into a boreportion 121 which cams the collet finger cam heads 118 radially inwardinto locking engagement with the tool chuck retention knob 120. When thedraw bar means 114 is operated so as to move the draw bar body 115 tothe right from the locking position shown in FIG. 14A, to a tool holderreleased position, the collet cam heads 118 are moved to the right intoan enlarged bore portion 124 which communicates with the tapered socket106. When the collet finger cam heads 118 are in the relaxed orinoperative position in the enlarged bore portion 124, they are in theposition shown in FIG. 16. That is, they are not flexed radiallyoutward, but the outer peripheries thereof form a cylindricalconfiguration with the outer configuration of the collet body 116. Theprior art type collet means all have collet fingers which are expandibleradially outward beyond the periphery of the corresponding collet body116 when in the released or inoperative position.

The collet body 116 is secured to the front end of the draw bar body 115by a suitable retainer bolt 122 which has an enlarged head 123 that isadapted to engage the tool chuck retention knob 120 when the draw barbody 115 is moved to the right from the locking position shown in FIG.14A so as to unlock the self-locking tool chuck 104. As shown in FIG.14A, the draw bar means 114 is in the operative or locking positionwherein the tool chuck 104 is held in a locked position in the taperedsocket 106 by the collet tool holding means comprising the collet body116, the collet fingers 117 and the collet cam heads 118.

As shown in FIG. 14A, the tool spindle body 87 is provided in the rearend portion thereof with an enlarged axial bore 125 which is made to alarger diameter than the central bore 113 with which it communicates. Adraw bar spring 126 is mounted in the bore 125 with its forward enddisposed against a shoulder 127 formed at the junction of the bores 113and 125. The rear end of the spring 126 is seated against an integralperipheral flange 130 on the draw bar body 115. It will be seen thatwhen the spring 126 is in the position shown in FIG. 14A that it holdsthe draw bar body 115 in the operative tool holder locking position. Thedraw bar means 114 can be moved to the right from the position shown inFIG. 14A against the retractive force of the spring 126 by a draw barrelease means described more fully hereinafter. A retainer ring 131 ismounted in the bore 125 in a position outward of the flange 130 toretain the draw bar means 114 in the tool spindle body 87. The numeral132 in FIG. 14A indicates the position of the rear end of the draw barbody 115 when the draw bar means 114 is moved to the right to theinoperative or tool holder released position.

As illustrated in FIG. 14A, a high response direct current electricservo motor, generally indicated by the numeral 135, is operativelymounted on the rear side of the spindle slide housing 46, for driving adrive gear means 136 for rotating the tool spindle 47 by means of thefollowing described structure. Motor 135 is provided with a mountingflange 138 that is seated on the enlarged portion 137 of the spindlehousing rear wall 55. The motor mounting flange 138 is secured to thehousing wall 137 by suitable machine screws 139.

As shown in FIG. 14A, the spindle drive motor 135 is provided with anoutput shaft 142, which is operatively connected to the enlarged inputend 144 of a drive gear shaft 143. The motor output shaft 142 isconnected to the shaft end 144 by a suitable key 145 and a spacer 146.The gear shaft 143 is provided with an enlarged diameter journal 147 atthe front end which is rotatably supported by a suitable ball bearingmeans, generally indicated by the numeral 150. The bearing means 150 isoperatively mounted in a bore 151 formed through the spindle housingfront wall 49, and it is engaged on its outer side by a cover plate 152which is secured in place by suitable button socket head screws 153.

The gear shaft 143 is provided with an enlarged journal portion 154around which is operatively mounted a gear supporting ball bearingmeans, generally indicated by the numeral 155. The inner race of thebearing means 155 is seated between the enlarged shaft portion 144 andshoulders 156 formed on the left sides of two drive keys 159. The outerrace of the bearing means 155 is operatively mounted in a bore 160formed axially in a pinion gear 161. The outer bearing race of thebearing means 155 is held against a shoulder formed in the bore 160 by asuitable retainer ring 162. It will be seen that the pinion gear 161 ismounted on the gear shaft 143 in a freely rotatable condition.

The pinion gear 161 is meshed with and adapted to drive a largerdiameter low speed gear 163 which is mounted on the tool spindle body 87and operatively connected thereto by a suitable key 164. The low speedgear 163 is seated against the rear end of a spacer sleeve 165 andretained thereagainst by a retainer ring 166.

As shown in FIG. 14A, a ball bearing means, generally indicated by thenumeral 171, is operatively mounted on the front end journal 147 of thegear shaft 143. The outer race of the bearing means 171 is seated in abore 172 formed axially through a large diameter high speed gear 173.The outer bearing race of the bearing means 171 is secured in place by aretainer ring 175. The inner end of the last mentioned outer bearingrace is seated against shoulders 174 formed on the right sides of thetwo drive keys of the clutch mounting sleeve 159. The bearings 150 and171 are retained in their spaced apart positions by a spacer sleeve 176.It will be seen that the high speed gear 173 is mounted by the bearingmeans 171 on the gear shaft 143 in a freely rotatable condition. Asshown in FIG. 14A, the high speed gear 173 is meshed with a pinion gear179 which is operatively mounted on the tool spindle body 87. The piniongear 179 is locked in place on the tool spindle body 87, against theforward end of the spacer sleeve 165, by a suitable key 180. The gear179 has its front end seated against a shoulder 181 formed on the toolspindle body 87. As shown in FIG. 14A, a gear clutch, generallyindicated by the numeral 182, is provided for selective connection ofeither the low speed gear 163 or the high speed gear 173 to the gearshaft 143 to provide a desired driving rotation to the tool spindle 47.As shown in FIG. 19, the clutch 182 is a gear type or spline clutchwhich has an axial bore 183 in which is slidably received the driveshaft 143. As shown in FIG. 19, a pair of diametrically disposed keys159 are slidably mounted in mating slots 184 and 185 formed in theclutch 182 and gear shaft 143, respectively. As shown in FIG. 20, theclutch 182 is provided with two peripheral sets of spaced apart gearteeth 189 and 190 which are spaced apart by a peripheral groove 193. Asshown in FIGS. 19 and 20, each of the gear teeth 189 and 190 is providedwith chamfers 191 along the side faces thereof which are sloped so as toconverge outwardly. The outer, upper edges of each of the teeth 189 and190 are also chamfered, as indicated by the numerals 192.

As shown in FIG. 14A, a clutch shifter disc 194 is secured by machinescrew 195 to one end of a piston rod 196. The piston rod 196 is slidablymounted through a bore 200 in a housing 201 which is carried on theinside of the spindle housing rear wall 55. The bore 200 communicateswith a spring chamber 202 in which is operatively mounted a coil spring203. One end of the spring 203 is seated against the front end of thespring chamber 202, and the other end abuts the front end of a piston204 which is integral with the rod 196 and slidably mounted in acylinder 205 formed in the enlarged housing wall portion 137 of the rearhousing wall 55. The piston 204 is provided with a suitable O-ring seal206. A passage 210 is formed in the housing wall portion 137, and it hasits inner end in communication with the rear end 209 of the pistoncylinder 205. The outer end of the passage 210 is adapted to beconnected to a suitable source of air under pressure for admitting airunder pressure into the cylinder 205 for moving the piston 204 forwardlyinto the advanced position shown in FIG. 14A against the pressure ofspring 203 to move the clutch 182 into the position shown in FIG. 14A toconnect the drive motor 135 with the high speed drive gear 173. When theair pressure is exhausted from the cylinder 205, the spring 203 movesthe shifter disc 194 to the left, from the position shown in FIG. 14A,and the piston 204 will be moved rearwardly or to the left as viewed inFIG. 14A into abutment with the end 209 of the piston chamber 205. Inthe last mentioned position, the clutch 182 would be moved to the leftto engage the pinion gear 161 for driving the low speed drive gear 163.In the position shown in FIG. 14A the clutch gear teeth 190 are inoperative driving relationship with the internal mating teeth 207 formedin the high speed gear 173. When the clutch 182 is moved to the left,the clutch or spline teeth 189 are moved into driving engagement withthe internal teeth 208 formed in the gear 161. The function of thechamfers 191 and 192 on the clutch teeth 189 and 190 is to permitefficient meshing of the gear clutch 182 with either the gear teeth 207on the gear 173 or the gear teeth 208 on the gear 161. An enclosed typemicroswitch 211 is secured by suitable machine screws 212 in the housingwall 137 in a position for operative engagement with the piston 204 whenit is moved between the advanced position shown in FIG. 14A and itsretracted position, or a position moved to the left from that shown inFIG. 14A. It will be understood that the drive motor 135 drives the toolspindle 47 clockwise or counterclockwise, through either the low speedgear 161 or the high speed gear 173.

It will be seen that the clutch 182 provides the spindle 47 with twospeed ranges relative to the speed of the drive motor 135. The drivemotor 135 rotates the spindle 47 in a clockwise or counterclockwisedirection. It will also be seen that spring 203 shifts the spindle drivemeans into the low range, while air pressure is employed to shift thedrive means into the high range. The micro-switch 211 signals that thespindle drive means is either in the high range or the low range. Anysuitable pneumatic controls may be provided for feeding the pressurizedair in and out of the cylinder 205 for operating the clutch shift piston204.

As shown in FIGS. 7, 8 and 14, the tool spindle slide assembly 12 ismoved upwardly and downwardly along the "Y" axis by a ball screwassembly, generally indicated by the numeral 214. As shown in FIG. 14,the lower end 215 of the lead screw for the ball screw assembly 214 isrotatably mounted in a suitable bearing means (not shown) which is heldin a support bracket 216. The support bracket 216 is secured by suitablemachine screws 219 to a mounting pad 220 that is fixedly carried on thecolumn assembly front wall 34. As shown in FIG. 14, the upper end of theball screw assembly 214 is rotatably mounted in a pair of ball bearingmeans 221 which are seated in a bore 222 formed in a downward extendedportion of a mounting plate 245. As shown in FIG. 14, the mounting plate245 is secured to the column assembly top wall 45 by any suitable means,as by suitable machine screws 251. The bearing means 221 are retained inthe bore 222 by a retainer plate 223 secured in place by suitablemachine screws 224. The ball screw assembly 214 is secured in placeaxially by a spacer 225 and a lock nut 226, which is threadably mountedon the upper end thereof. As illustrated in FIGS. 14 and 15, the upperend 228 of the ball screw assembly 214 is operatively connected by a key230 and set screws 231 to the hollow output shaft 227 of a directcurrent servo motor, generally indicated by the numeral 229, which issimilar to the spindle drive motor 135. The drive motor 229 has amounting flange 246 which is secured to the mounting plate 245 bysuitable machine screws 247.

As shown in FIG. 14, a stop member 235 is carried on the upper end ofthe lead screw nut mounting plate 233 for operative engagement with astop member 242 when the spindle housing 46 reaches the upper end of itstravel. A stop ring 238 is fixed by suitable machine screws 241 to thelower side of the housing lower wall 51. The stop ring 238 carries astop member 243 which engages the stop member 244 when the spindlehousing 46 reaches the lower end of its travel. As illustrated in FIG.11, the ball screw assembly 214 is provided with lubricant through anoil fitting 240 which is connected by a nylon tubing 239 to thelubricant distribution unit 80.

As shown in FIGS. 12 and 14, the tool spindle slide assembly 12 includesa pivotally mounted and mechanically operated wedge means, generallyindicated by the numeral 248, which radially locates the position of thetool chuck 104 and the respective tool 108 carried therein, and whichalso releases or unlocks the tool chuck 104 from the tapered socket 106in the tool spindle 47. The unlocking and locating wedge means 248 issubstantially triangular in side elevation view, as shown in FIG. 14.The wedge means 248 is swingably mounted in a slot 249 (FIG. 11) whichis formed in the rear face of a pivot block 250. The pivot block 250 issecured to the rear face of the spindle housing rear wall 55 by aplurality of suitable machine screws 254. The wedge means 248 is pivotedat its inner upper corner in the slot 249 by a suitable dowel pivot pin253. As shown in FIG. 14, the wedge means 248 is normally biased in aclockwise direction, into an inoperative position shown in FIG. 14, by asuitable coil spring 265 which has its inner end seated in a recess 266(FIG. 14A) formed in the inner surface 260 of the slot 249 in the pivotblock 250, in a position facing the slot 249. The outer end of thespring 265 is seated in a recess 264 which is formed on the inner faceof the wedge means 248.

As shown in FIG. 14A, when the wedge means 248 is pivoted in acounterclockwise direction or inwardly toward the spindle 47, asdescribed hereinafter, the wedge means 248 assumes an operative positionindicated by the numeral 248a. When the wedge means 248 is in theoperative position 248a, the upper side 255 thereof (FIG. 14) issubstantially horizontal and parallel to the top of the spindle housing46. An integral, upwardly extended projection or stop member 256 isformed on the upper outer end of the wedge means 248. When the toolspindle slide assembly 12 is moved upwardly to the position shown inFIG. 14, the stop member 256 on the wedge means 248 engages the lowerflat end 257 formed on the bottom end of a positive stop block 258.Continued upward movement of the tool spindle slide assembly 12 forabout the last one inch of upward travel mechanically pivots the wedgemeans 248 in a counterclockwise direction, as viewed in FIG. 14, to moveit into the operative position 248a, as shown in FIG. 14A. The positivestop block 258 is secured to the underside of the mounting block 245 byany suitable means, as by suitable machine screws 261.

As shown in FIG. 14, when the wedge means 248 is biased to the solidline, inoperative position, the wedge means has an angle contact surface263, which is formed along the upper inner edge thereof, and which isadapted to abut against an inner surface 260 of the slot 249. Thecontact surface 263 is angled inwardly toward the wedge means upper endsurface 255, and its lower end terminates at the upper end of a secondcontact surface 262 which is adapted to be seated against the slot innersurface 260 when the wedge means 248 is cammed in a counterclockwisedirection to the operative broken line position, indicated by the line248a in FIGS. 14 and 14A, for unlocking the tool spindle 47.

As stated hereinbefore, when the tool spindle slide assembly 12 reachesits approximately last one inch of upward travel, the stop member 256,on the upper end of the wedge means 248, engages the positive stop block258 and cams the wedge means 248 in a counterclockwise direction, asviewed in FIG. 14. As shown in FIG. 14A, the wedge means 248 has anoutwardly extended contact end 267, on the inner side therof, which hasa first contact surface 268 on the upper outer edge that is adapted tobe moved into a transverse slot 272 formed in the outer rear end of thetool spindle 47. Continued upward movement of the tool spindle slideassembly 12 moves the wedge means 248 in the counterclockwise directionso as to move the contact end 267 further inwardly, into the adjacentslot 273 formed in the rear end of the tool spindle 47, and to bring thecontact surface 268 into engagement with the rear end of the drawbarbody 115. Continued pivoting inward movement of the wedging means 248pivots the contact surface 268 upwardly off of the rear end of the drawbar body 115, and brings the lower contact surface 271 on the wedgingmeans contact end 267 into sliding engagement with the rear end of thedraw bar body 115. It will be seen that the wedge means contact surfaces268 and 271 are angled rearwardly or toward the main body of the wedgingmeans 248. Continued counterclockwise movement of the wedging means 248,during the last portion of the upward travel of the tool spindle slideassembly 12, moves the draw bar body 115 to the right, as viewed inFIGS. 14 and 14A, so as to engage the draw bar head 123 with theretainer knob 120 of the tool chuck 104 for unlocking the tool chuck104. When the last mentioned condition is reached, the stop member 256is then seated flat against the lower flat or horizontal surface 257 ofthe positive stop block 258. As shown in FIG. 12, the outer slot 272 inthe rear end of the tool spindle 47 is made to a larger width than thewidth of the inner slot 273, so as to allow the wedging means 248 toenter the slot 273 before the tool spindle 47 is finally located in itsfinal position. When the wedging means 248 enters the inner slot 272, itenters said slot in a sliding relation so as to radially locate the toolspindle 47 in the desired tool changing position, with the tool chuck104 in a desired tool changing position and in an unlocked condition. Itwill be seen that the wedge means 248 knifes its way into the slots 272and 273, and then radially locates the tool spindle 47 and unlocks thetool chuck 104 in a purely positive mechanical action. The tool spindle47 is roughly located relative to its finally desired radial position,by the following described magnet means and sensing means.

As illustrated in FIGS. 12 and 13, the low speed gear 163 of the toolspindle drive gear means has a bore 274 formed therethrough in which isoperatively mounted, as by a press fit, a cylindrical permanent magnet275. As shown in FIG. 13, the outer face of the permanent magnet 275 ispositioned adjacent the rear face 279 of the low speed gear 163. In oneembodiment the magnet 275 is 3/8 of an inch in diameter. A conventionalproximity switch 276 is fixed by a suitable socket head screw 277 on aswitch support arm 278 in a position axially spaced apart from themagnet 275. The support arm 278 and the proximity switch 276 arepositioned in a bore 281 formed through the spindle housing rear endwall 55. The switch support arm 278 is fixed, as by welding, to theinner face of a switch bracket 282 which comprises a plate that ismounted over the outer side of the bore 281 and secured in position bysuitable machine screws 283. The machine screws 283 pass throughsuitable slots 280 formed in the switch bracket 282 to permit thebracket 282 to be adjusted, for adjusting the position of the proximityswitch 276 relative to the magnet 275 when the gear 163 and spindle 47are in the desired tool change position to radially locate the toolspindle 47 and the tool chuck 104 carried therein. A suitable proximityswitch is one available on the market from Hamlin Inc., Lake End andGrove Streets, Lake Mills, Wis., and sold under Model No. 5901.

As shown in FIGS. 7, 11 and 12, a micro-switch, generally indicated bythe numeral 284, is fixedly mounted on the upper end of the rear face ofthe tool spindle housing rear wall 55 by any suitable means. As bestseen in FIG. 7, an elongated threaded rod 285 is threadably mountedthrough the mounting plate 245, and it is fixed in a desired adjustedposition by a lock nut 286. The lower end of the threaded rod 285 isadapted to be engaged by the micro-switch 284 when the tool spindleslide assembly 12 reaches the end of its upward travel so as to shut offthe drive motor 229 for the "Y" axis ball screw assembly 214. The drivemotor 135 for the tool spindle 47 would have been previously shut offwhen the tool spindle slide assembly 12 reaches the position shown inFIG. 14, at the point where the tool spindle slide assembly 12 isentering its last one inch of travel. The spindle drive motor 135 isprogrammed to turn through a slow index cycle preparatory to stopping,and when the magnet 275 reaches the position shown in FIG. 13, oppositeto the proximity switch 276, a signal is created which shuts off thepower to the tool spindle drive motor 135, and the tool spindle 47 stopsin a location where it is roughly located, radially, in a desired toolchanging position. The aforedescribed inward swinging movement of thewedge means 248 into the tool spindle slots 272 and 273 carries out thefinal radial locating of the tool spindle 47, and the unlocking of thetool chuck 104 carried in the tool spindle 47.

As shown in FIGS. 1 and 7, the tool spindle slide assembly 12 isprovided with a bellows 287 on the upper end thereof for protectionagainst dirt. As shown in FIG. 7, the upper end of the bellows 287 isattached by a suitable mounted plate means 288 to the underside of themounting plate 247. The lower end of the bellows 287 is fixed by asuitable bellows mounting plate 291 to the top of the tool spindle slideassembly 12. As shown in FIG. 8, a similar bellows 292 is also mountedon the lower side of the tool spindle slide assembly 12, and with theupper end thereof being attachable to the lower end of the tool spindleslide assembly 12 by a mounting plate similar to the mounting plate 291.The lower end of the bellows 292 is fixed by any suitable means, as bymachine screws 293, to the front side of the column assembly front wall34.

Tool Storage and Tool Changer Carousel Means

As shown in FIG. 22, the tool storage and tool changer carousel means 13includes a carousel wheel or circular plate 296 which is provided with acentral bore 297. The carousel wheel 296 is rotatably mounted on thecircular hub 298 of a circular carrier plate 301 by a suitable needlebearing means 300. The carrier plate hub 298 extends forwardly beyondthe carousel wheel 296 into a circular recess 302 which is formed in theinner side of a circular retainer plate 303. The retainer plate 303retains the carousel wheel 296 on the carrier plate 301. The retainerplate 303 is secured in place by suitable machine screws 304.

As shown in FIG. 22, the front end 305 of a square carrier shaft,generally indicated by the numeral 306, is fixedly secured to a mountingspacer plate 309 on the rear face of the carrier plate 301, by anysuitable means, as by welding. The square carrier shaft 306 is slidablymounted in a square bore 307 in a support housing 308. The supporthousing 308 is fixed on the mounting plate 245 by any suitable means, asby suitable machine screws 311. The rear end of the square carrier shaft306 is fixed by suitable mounting screws 313 to a mounting plate 312.The mounting plate 312 is fixedly secured to the outer end of a cylinderrod 314 of a suitable air cylinder, generally indicated by the numeral315, and which is adapted to be connected to a suitable source of airunder pressure. The air cylinder 315 is provided with a mounting flange316 which is secured by machine screws 317 to the vertical flange 318 ofa suitable mounting bracket which has an integral horizontal flange 319that is secured by suitable machine screws 320 to the mounting block245. It will be seen that the cylinder rod 314 is in the retractedposition, and accordingly, the carrier shaft 306 and the carousel 13 arein the retracted or tool changing position. When the air cylinder 315 isenergized to move the cylinder rod 314 outwardly, the carousel 13 ismoved outwardly from the retracted tool changing position shown in 22away from the stationary support housing 308 to the advanced positionshown in FIG. 48, and which is indicated by the numeral 13a. In theadvanced position 13a, the carousel 13 may be rotated in a clockwise orcounterclockwise direction to bring the next desired tool into a toolchanging position, after which the carousel means 13 is then retractedto the solid line position shown in FIG. 14 and FIG. 22.

The carousel means 13 is rotated by a suitable alternating currentelectric motor, generally indicated by the numeral 324 in FIG. 22. Thedrive motor 324 is a suitable gear motor with a disc brake 323. Thecarousel drive motor 324 is fixedly mounted on a carrier arm 325 whichis secured to a carrier plate 326 that is secured to one side of thesquare carrier shaft 306 for moving the drive motor 324 in unison withthe carousel 13. The carrier arm 325 and carrier plate 326 are slidablymounted between a pair of keeper plates 328 which are fixed to thestationary support housing 308 by any suitable means, as by machinescrews 327. As shown in FIG. 21, a pinion drive gear 333 is fixedlysecured to the output shaft 332 of the drive motor 324 by a suitable key334. Pinion gear 333 meshes with and drives a carousel drive gear 335which is fixedly secured to the carousel plate 296 by a plurality ofsuitable machine screws 337. Machine screws 337 extend through thecarousel wheel 296 and through suitable spacers 336 and into threadedholes 338 formed in the gear 335.

As shown in FIG. 22, a hexagonal head machine screw 341 is adjustablymounted on the rear face of the carrier plate 301 for actuating amicro-switch 342 which is secured by machine screw 343 to one side ofthe fixed housing 308. The machine screw 341 functions as a switchoperator for engaging the micro-switch 342, for actuating the same whenthe carousel means 13 reaches the retracted position, as shown in FIG.22, at the end of a retractive movement to provide a control signal.

A micro-switch 354 is mounted on top of the fixed housing 308 andincludes a housing 355 which is secured by a machine screw 356 to thetop of the housing 308. The micro-switch 354 is adapted to be actuatedby the mounting plate 312 when the square carrier shaft 306 is advancedinto the fully extended position, as indicated in FIG. 48, by thenumeral 13a. The air cylinder 315 is adapted to be operated by asuitable signal which, when it is energized to extend the carousel means13 outwardly, the drive motor 324 is also energized for rotating thecarousel means 13 in the desired direction. The drive motor 324 isadapted to rotate the carousel 13 in a desired direction at a desiredr.p.m., as for example, in one embodiment the carousel 13 is rotated at3 r.p.m. It will be seen that the square carrier shaft 306 functionswith the fixed housing 308 to provide a transverse slide means for thetool storage carousel means 13.

As shown in FIG. 22, a switch mounting bracket 345 is fixed by suitablemachine screws 346 to the outer side of the housing of the motor 324, soas to be carried therewith. A pair of micro-switches 347 and 349 arefixed in a side-by-side position on the bracket 345, by a suitablemachine screw 351. The micro-switches 347 and 349 are provided withoperating arms 348 and 350, respectively, which are adapted to engagethe slots 357 as the carousel wheel 296 is rotated, for a countingfunction as explained more fully hereinafter. As illustrated in FIG. 21,each of the slots 357 is disposed on a radius line, and they areelongated and disposed at the innermost point of a tool receiving seator socket 358. As shown in FIG. 1, the carousel means 13 is providedwith 24 of the tool slots 358. Each of the tool slots 358 issemi-circular in plan configuration. As shown in FIG. 21, a locatorfinger 361 in the form of an elongated bar is slidably mounted in theouter end of the radial slots 357 and secured in an adjusted position bya suitable machine screw 362. The locator fingers 361 are adapted toengage in the annular groove 107 on a tool chuck 104 during a toolchanging operation, and when a tool chuck 104 is inserted into one ofthe tool slots 358.

As shown in FIG. 22, an annular retainer plate 363 is mounted on theouter face of the carousel wheel 296, and it is provided with a centralhole 364 therethrough for mounting the plate 363 around the retainerplate 303. The retainer plate 363 is secured in position on the carouselwheel 296 by suitable machine screws 365.

As shown in FIG. 21, a tool retainer clip, generally indicated by thenumeral 367, is fixedly secured by a suitable machine screw 368 on eachof the outer peripheral faces 369 of the radially extended arms 370 onthe carousel wheel 296 that form the tool seats or slots 358. Each ofthe tool retainer clips 367 is provided with a pair of sidewardlyextended clip arms 371, so as to provide a clip arm 371 on each side ofeach tool slot 358. It will be seen from FIG. 48 that when the toolspindle 47 is moved from a lowered, metal cutting position indicated bythe broken line spindle 47a, to a raised tool changing positionindicated by a solid line spindle 47, that the tool chuck 104 carried inthe tool spindle will be moved into the lowermost tool slot 358 on thecarousel wheel 296. The spring clip arms 371 function to grip the sidesof a tool chuck 104 when it is inserted into a tool slot 358 andreleasably retain the same therein. It will be understood that each ofthe tool slots 358 will have retained therein a tool chuck 104 by meansof spring clip arms 371. As shown in FIG. 8, the carousel means 13 maybe provided with a suitable cover means 375 which is provided with aflange 376 on each side thereof. The flanges 376 are adapted to besecured to the top of the control panels 20 and 21 by suitable machinescrews 377.

"X" Axis Base

As shown in FIGS. 23, 24 and 25, the "X" axis base 14 is provided withintegral flanges on the front and rear thereof which are adapted formounting conventional leveling screws 382. As illustrated in FIG. 24,the base 14 is substantially rectangular in overall plan view, and issecured by suitable machine screws 383 to a mounting flange structure384 formed on the front of the column assembly 11 (FIG. 8). As shown inFIGS. 24 and 25, the base 14 is provided with a pair of laterally spacedapart conventional "X" axis ways 385 which are integrally formed on theupper front and rear side edges of the base 14. The base 14 has asuitable coolant reservoir formed therein which is operatively connectedto a coolant pump 386 for supplying coolant to the workcenter. Thenumeral 380, in FIG. 23, designates the coolant reservoir cover. Asshown in FIGS. 7 and 25, the lubricant pump or supply unit 84 supplieslubricant through a nylon tubing 83 to the fitting 388, and thencethrough a nylon tubing 387 to a nylon tubing 401 on the saddle slideassembly 15. As shown in FIG. 9, the lube oil is fed from the fitting388 through a nylon tubing 389 to the aforedescribed lube oil fitting 82which supplies lube oil to the tool spindle slide assembly 12.

Saddle Slide Assembly

As shown in FIGS. 23, 24 and 25, the saddle slide assembly 15 isslidably mounted on the ways 385 on the base 14, and it is moved alongthe ways 385 by a conventional lead screw or ball screw assembly 391.The lead screw 391 is operatively mounted through a lead screw nut 392which is fixedly mounted on the left side of the saddle assembly 15, asviewed in FIG. 24. As shown in FIG. 23, the outer end of the lead screw391 is operatively connected to the output shaft of a direct currentservo motor, generally indicated by the numeral 393. The motor 393 isthe same type of motor as is employed for the "Y" axis drive motor 229and the tool spindle drive motor 135. The "X" axis drive motor 393 iscarried on a suitable mounting bracket 394 which is supported on theleft side of the base 14. As shown in FIG. 23, the saddle slide assembly15 is provided with a limit switch 395 which is adapted to engage thelongitudinally spaced apart trip dogs 396 and 397 for limiting thelongitudinal movement of the saddle slide assembly 15 on the "X" ways385. In one embodiment, the trip dogs were spaced about 24 inches apartto limit the travel of the saddle slide assembly 15 to 24 inches. Asshown in FIG. 28, the saddle slide assembly 15 is provided with suitableway keeper 398 on the left side thereof for operative engagement withthe ways 385 on the base 14. As shown in FIG. 28, the right side of thesaddle slide assembly 15 is also provided with suitable way keeper 400for operative engagement with the ways 385. The lube oil pump 84supplies fluid through the tubing 401 which conveys lubricant to adistribution fitting 402 which is carried on the left side of the saddleslide assembly 15, as shown in FIGS. 27 and 28. The lube oil is conveyedfrom the fitting 402 by tubing 403 to the lead screw 391, and throughother suitable tubings into the saddle slide assembly 15 for appropriatelubrication purposes. As shown in FIGS. 23 and 24, the saddle slideassembly 15 is provided with a pair of "Z" axis ways 405 which aredisposed transverse to the "X" axis ways 385.

Work Table Assembly

As shown in FIGS. 28 and 29, the work table assembly 16 is slidablymounted on the ways 405 on the saddle slide assembly 15, and it is movedalong the ways 405 by a conventional lead screw or ball screw assembly407. The lead screw 407 is operatively mounted through a lead screw nut408 which is fixedly mounted in the front end of the work table assembly16, as viewed in FIG. 28. As shown in FIG. 28, the outer end of the leadscrew 407 is operatively connected to the output shaft of a directcurrent servo motor, generally indicated by the numeral 411. The motor411 is the same type of motor as is employed for the "Y" axis drivemotor 229, the "X" axis drive motor 393 and the tool spindle drive motor135. The "Z" axis drive motor 411 is carried on a suitable mountingbracket 412 which is supported on the front side of the saddle slideassembly 15. As shown in FIGS. 26, 27 and 28, a limit switch 413 isfixed on the top of the saddle slide assembly 15, and it is adapted tobe engaged by trip screws for limiting the transverse movement of thework table assembly 16 on the "Z" axis ways 405.

As shown in FIGS. 33 and 35, a trip bracket 414 is fixedly secured onthe left side of the work table assembly 16, and it depends downwardlyalong the side thereof. The trip bracket 414 carries a trip screw 415which is adjustably mounted, and which is adapted to engage the limitswitch 413 when the work table assembly 16 is moved inwardly. FIG. 36 isan inverted rear end view of the work table assembly 16, and it shows asecond depending trip bracket 416 which is carried adjacent the leftrear end of the work table assembly 16, and which is provided with asecond trip screw 417 for engagement with the limit switch 413 when thework table assembly 16 is moved outwardly. As shown in FIG. 37, the worktable assembly 16 is provided along the rear face thereof with a waywiper 418. As shown in FIG. 38, the front end of the work table assembly16 is also provided with a way wiper 421 across the front end thereof.

In one embodiment, the normal working travel of the work table assembly16 on the saddle slide assembly 15 along the "Z" axis is about 16inches, with an additional inch of outward travel being provided if themachining center is provided with the optional pallet changer, as isexplained more fully hereinafter. As shown in FIGS. 27 and 28, a tubing422 feeds lubricant from the lubricant fitting 402 through the saddleassembly 15 to a junction fitting 423. As shown in FIG. 36, the fitting423 is connected by a nylon flexible tubing 424 to a fitting 425 carriedon the front of the work table assembly 16. Lube oil is fed from thefitting 425 through a tubing 426 and a fitting 427 to the work tableassembly lead screw 407.

Work Table

FIGS. 30 through 34 illustrate a work table assembly 16 which isprovided with a rotatable work table 17 (FIGS. 33, 34) which is notprovided with the optional pallet changer apparatus. As shown in FIGS.30 and 33, the work table 17 is provided with a cylindrical tablespindle 428 which is secured to the bottom side thereof by suitablemachine screws 429 and suitable fixture keys 430. The table spindle 428is seated within a circular opening 433 which extends down into the topof the work table assembly 16. A suitable thrust roller bearing means434 rotatably supports the table spindle 428 in the circular opening433. The table spindle 428 is provided on the lower inner end thereofwith an integral circular flange 435 which is mounted in an enlargedcircular chamber 436 that is formed in the bottom of the work tableassembly 16 and which communicates with the upper circular opening 433.

As shown in FIG. 33, a gear 437 is carried on the upper face of theflange 435 and it is fixedly secured thereto by suitable machine screws438. The gear 437 meshes with and is driven by a worm gear 441 which iscarried on a drive shaft 442 that is mounted in an elongated bore 440formed in the work table assembly 16. As shown in FIG. 32, a worm gear441 is fixed to the drive shaft 442 by a suitable key 443 and a lock nut445 which holds the worm gear 441 against the outer end of the largediameter shaft portion 444 of the drive shaft 442. The enlarged portion444 of the drive shaft 442 is rotatably mounted in a pair of suitableball bearing means 446 which are supported in the inner end of a bearingmounting sleeve 448. A spacer sleeve 447 is mounted between the outerbearing means 446 and the adjacent end of the worm gear 441. The bearingmounting sleeve 448 is fixedly mounted in an enlarged outer end portion451 of the bore 440. The outer end of the drive shaft 442 is rotatablysupported by a pair of ball bearing means 452 which are seated in aperipheral recess formed in the inner periphery of the mounting sleeve448 and held in place by an enlarged diameter portion 453 of the driveshaft 442. As shown in FIG. 32, the bearing mounting sleeve 448 isprovided on its outer end with a mounting flange 454 which is seated onan inwardly directed flange of a motor mounting bracket 455. Themounting sleeve flange 454 is secured to the flange on the motormounting bracket 455 by suitable machine screws 456. As shown in FIG.30, the motor mounting bracket 455 is fixed to the work table assembly16 by suitable machine screws 457.

A direct current servo drive motor, generally indicated by the numeral458, is provided for driving the rotary work table 17. As shown in FIG.32, the drive motor 458 is provided with a mounting flange 459 which issecured by machine screws 460 and washers 462 to the mounting bracket455. The machine screws 460 pass through arcuate slots 461 which permitthe motor 458 to be rotatably adjusted, for adjusting the properbacklash between the worm gear 441 and the gear 437. The drive motor 458is provided with an output shaft 463 which receives the outer end 464 ofthe drive shaft 442. The motor output shaft 463 is connected to thedrive shaft end 464 by a suitable set screw 465 (FIG. 32) and a key 466(FIG. 31).

The rotary work table drive motor 458 rotates the work table 17 in a360° rotary movement. As shown in FIG. 34, a limit switch 467 is mountedin the upper side of the work table 16, and it is adapted to be engagedby a trip dog 468 on the work table 17 for indicating that the table hasbeen rotated 360°, and for control purposes, as desired. The drive motor458 is of the same type direct current drive motor as employed fordriving the tool spindle 47 and for the "X", "Y" and "Z" axes drivemotors.

Optional Pallet Changer

The optional pallet changer is generally indicated by the numeral 22 inFIG. 1, and it is disposed at the right side of the "X" axis base 14.When the optional pallet changer 22 is employed, the work table assembly16 previously described is modified so as to permit the use of a pair ofinterchangable pallets, as indicated by the numerals 18 and 19 inFIG. 1. While the pallet 18 is holding a workpiece for cuttingoperations thereon by a tool 108, the other pallet 19 may be processedby removing a finished workpiece therefrom and replacing it with a newworkpiece. The pallet 19 then subsequently replaces the pallet 18 in themetal cutting position relative to the tool spindle slide assembly 12.

As shown in FIG. 39, the work table assembly 16 is modified when thepallet changer 22 is employed, however the modified work table assembly16 is still provided with the same rotary drive structure as describedhereinbefore in relation to the work table shown in FIGS. 30 through 34,and the same reference numerals have been applied to said rotary drivestructure in FIGS. 39, 40 and 41. It will be seen from the structureshown in FIG. 39, that when the pallet changer 22 is used, the worktable 17 is replaced by an inverted T-shaped base member, generallyindicated by the numeral 474. The base member 474 is provided with acentral raised rectangular portion 475 which is secured like the worktable 17, in the first described table embodiment, by suitable machinescrews 429 to the previously described table spindle 428. The basemember 474 is provided with a pair of integral side base plates 479which extend sidewardly from the central raised portion 475, as shown inFIG. 39. A rectangular clamp plate 477 is secured by suitable machinescrews 478 to the top end of a cylindrical shaft 481. As shown in FIGS.39 and 41, the shaft 481 is slidably mounted for vertical movement in acylindrical bore 482 formed in the central raised portion 475 of thebase member 474. A suitable 0-ring seal 483 is operatively mountedaround the lower inner end of the shaft 481. As shown in FIG. 39, thelower end of the bore 482 is indicated by the numeral 484.

As shown in FIGS. 39 and 40, a vertical shaft 485, which is formed to adiameter smaller than the diameter of the shaft 481, is integrallyformed on the lower end of the shaft 481, and it extends downwardlythrough a bore 486 which is formed through the spindle 426. As shown inFIG. 39, a flange 487 is mounted on a reduced diameter, threaded lowerend 488 of the shaft 485, and it is secured in place by a suitable locknut 489. A plurality of axial spring bores 492 are formed in the spindle428, in the lower end thereof, and they extend upwardly around the shaftbore 486. A compression spring 493 is operatively mounted in each of thespring bores 492, and the lower ends thereof bear against the flange 487for normally biasing the shaft 485 in the clamp plate 477 downwardly tobring the clamp plate 477 into a clamping engagement with a pallet 18carried on the base member 474.

As shown in FIG. 39, each of the pallets, as the pallet 18, is providedon its lower side with a longitudinal, T-shaped slot formed therethroughwhich comprises an upper transverse portion 494 and a lower verticalportion 496. The base member 474 is received in the lower verticalportion 496 of the longitudinal T-shaped slot, and the clamp plate 477is received in the transverse or horizontal portion 494. When thesprings 493 move the clamp plate 477 downwardly, it will be seen thatthe outer end portions of the clamp plate 477 extend sidewardly beyondthe central raised portion 475 of the base member 474, and move into aclamping engagement with the shoulders 495 formed by the lower side ofthe transverse slot portions 494, so as to force the pallet 18downwardly into a clamping engagement on the side base plates 476.

The clamp plate 477 is released or unlocked from a pallet 18 during thelast inch of travel of the work table assembly 16 outwardly. That is, ifthe work table 16 moves outwardly for 16 inches of travel on the "Z"axis, then it is continued on for another inch, during which the pallet18 is unlocked. As shown in FIG. 38, the lower end 497 of the shaft 485is reduced in diameter, and it is slidably mounted through a sleevebushing 498 which is operatively mounted in a vertical bore 501 formedthrough a supporting plate 502 which is fixedly carried on the lower endof the work table assembly 16. A suitable 0-ring seal 503 is mounted onthe shaft portion 497. The lower end 497 of the shaft 485 is providedwith a conical end cam surface 506 which acts as a cam follower forengagement with a tapered cam surface 507 that is formed on the innerend of an unlocking cam wedge 504. The unlocking cam wedge 504 issecured by suitable machine screws 505 to the upper side of the saddleslide assembly 15. It will be seen that as the work table assembly 16 ismoved outwardly, or to the left as viewed in FIG. 39, during the lastone inch of travel, that the shaft 485 will be cammed upwardly to movethe clamping plate 477 upwardly from the clamping shoulders 495 on thepallet 18 to release the pallet and prepare it for a transfer operation,as described hereinafter.

As shown in FIGS. 41 and 42, a locating plate 511 is secured by machinescrews 512 on the rear end 513 of the raised central portion 475 of thebase member 474. As best seen in FIGS. 41 and 42, the locating plate 511extends upwardly above the raised central portion 475 of the base member474, and extends into a recess 514 formed in the lower face of the clampplate 477. It will be seen from FIG. 42, that the outer sides of thelocating plate 511 engage the vertical side edges 496 of the verticalportion of the T-shaped slot formed in the pallet 18 for locating thepallet axially. It also functions to prevent the clamp plate 477 fromrotating.

As shown in FIGS. 39 and 40, each of the base plates 475 is provided onwhat may be termed the front end thereof with a transverse integrallocating plate 515. As best seen in FIG. 41, each of the locating plates515 is provided with a longitudinal groove 516 on the upper sidethereof. A mating locating plate 517 is mounted on the front side of thepallet 18 above each of the locating plates 515 and secured to the outerlower face of the pallet by a pair of suitable machine screws 518. Asshown in FIG. 41, each of the locating plates 517 is provided with adownwardly extended locating tongue 521 which is adapted to be seated inthe adjacent groove 516 when the pallet is in a clamped position, asshown in FIGS. 39 and 41. The pallet 18 is not in a fully clampedposition, as shown in FIGS. 39 and 41, and the lower shaft end 497 ofthe shaft 485 is partially into its upward movement along the unlockingcam surface 507 for raising the pallet 18 upwardly. It will be seen inFIG. 41, that the locating tongue 521 is partially raised upwardly outof the groove 516. When the clamping plate 477 is moved upwardly to itscompletely unlocked position, the locating tongues 521 are raised clear.The clamping plate 477 lifts the pallet 18 upwardly from the locatingplates 515, so as to move the locating tongues 521 upwardly and out ofthe grooves 516 so that the lower ends of the locating tongues 521 areclear and above each of the locating plates 515 to permit the pallet 18to be slid off of the base member 474. It will be seen that the clampingplates 515 and 517 cooperate to give the pallet 18 a proper radiallocation on the base member 474.

As shown in FIGS. 43 and 44, the optional pallet changer 22 includes abase, generally indicated by the numeral 522, which is secured at thefront end thereof to the right side of the "X" axis base 14 by suitablemachine screws 523. The pallet changer base 522 is provided withsuitable leveling screws 524. FIG. 1 shows a pallet changer base 522which is slightly different in form than the base 522 shown in FIGS. 43and 44, but the difference in the base form does not affect the functionof the pallet changer. Also, the leveling screws 524 for the particularbase 522 shown in FIG. 1 are of slightly different configuration andstructure.

As shown in FIGS. 43 and 44, a substantially rectangular pallet changerhousing, generally indicated by the numeral 525, is operatively mountedon the top of the base 522 and it operatively supports an elongatedpallet supporting guide plate 526. As shown in FIG. 47, the palletsupporting guide plate 526 is secured by suitable machine screws 527 tothe upper end of the vertically disposed spindle or shaft 528. The guideplate supporting spindle 528 is rotatably mounted in a vertical bore 531which is formed in a spindle journal 532. The spindle journal 532 isintegrally formed with the pallet changer housing top wall 533.

As shown in FIG. 47, a reduced diameter drive shaft 534 is integrallyattached to the lower end of the spindle 528, and it is rotatablymounted in a suitable sleeve bearing 540 that is mounted in a bore 535formed vertically through a mounting plate 536. The mounting plate 536is secured by suitable machine screws 537 to the lower end of thespindle journal 532. A drive gear 538 is fixedly secured to the lowerend of the drive shaft 534 by a suitable key 542. A thrust washer 539 ismounted between the lower face of the mounting plate 536 and the drivegear 538. As shown in FIGS. 46 and 47, a switch operating arm 543 ismounted on the lower end of the drive shaft 534, and it is securedthereto by a retainer plate 544 and a machine screw 545.

As shown in FIG. 47, the drive gear 538 is meshed with and driven by apinion 546 which is fixed to the output shaft 547 of a direct currentservo gear motor, generally indicated by the numeral 548, by a suitablekey 552. The drive motor 548 is provided with a disc brake 549, and itis of the general type described hereinbefore for the carousel drivesystem employed in the workcenter. The pinion gear 546 has an axiallyextended tubular gear shaft 553 which extends upwardly and which isrotatably mounted in a suitable sleeve bearing 554 that is operativelyseated in a vertical bore 555 formed through the mounting plate 536. Amotor support bracket 556 is secured to the one end of the mountingplate 536 by suitable machine screws 557. The drive motor 548 is securedto the bracket 556 by suitable machine screws 558.

As shown in FIG. 46, the switch operating arm or lever 543 is adapted tooperate the limit switches 561 and 562 at the opposite ends of theoscillating rotatable travel of the guide plate 526. The limit switches561 and 562 are fixedly secured by any suitable means on the supportplate 536. The drive motor 548 is adapted to rotate the guide plate 526through a 180° turn and then reverse the guide plate to its initialposition. The limit switches 561 and 562 thus function to control theoscillating rotating movement of the guide plate 526.

As shown in FIG. 45, the guide plate 526 is provided with a pair ofspring biased detent plungers 563 and 564 which are adapted to beengaged with a suitable detent hole 565 that is formed on the upper endof the journal member 532 for releasably retaining the pallets to theguide 526 during an index cycle. As shown in FIGS. 45 and 46, adownwardly extended stop arm 566, which is square in cross section, isfixed on the underside of the guide plate 526, by any suitable means.The stop arm 566 is provided with a suitable O-ring 567 around the outersurface thereof to act as a bumper. In the position shown in FIG. 45,the stop member 566 is disposed against a stop member 568 that is fixedon the upper surface of the housing wall 533. A second stop member 569,which is identical to the stop member 568, is disposed on the housingtop wall 533 in an opposite position at the other end of the housing 525when the guide plate 526 is rotated 180° counterclockwise, as viewed inFIG. 46, from the position shown therein through a 180° turn.

As best seen in FIGS. 43 and 45, the pallet changer 22 is provided witha pallet transfer arm 574 that is integrally formed on the forward endof a vertically disposed carrier plate member 576 which is slidablymounted along the outer side of the housing side wall 592. The pallettransfer arm 574 is provided with a transverse notch 575 which is shapedlike, and adapted to receive, the locating tongue 521 formed on thelower side of an outward extension of one of the locating plates 517carried on each of the pallets to be transferred by the pallet changer22. As shown in FIGS. 46 and 47, the carrier plate 576 is secured bysuitable machine screws 577 to a guide bracket 573 and an attachmentbracket 579. The attachment bracket 579 is fixedly secured to a ballscrew nut 580. A sliding key member 578 is interposed between the outerface of the guide bracket 573 and the inner face of the carrier plate576, and it is adapted to be slidably mounted in a longitudinallyextended, elongated slot 596 formed through the housing side wall 592.As shown in FIG. 46, the rear end of the slot 596 communicates with anenlarged slot 595, whereby when the carrier plate 576 is in theretracted position shown in FIGS. 43 and 45, the cam key 578 will movedownwardly by cam action into the enlarged opening slot 595 to lower thetransfer arm 574 to the inoperative position shown in FIG. 45 where itis separated from the locating tongue 521a of a pallet 18a which hasbeen transferred onto the pallet guide plate 526. As shown in FIG. 47,the housing wall 592 is releasably secured to the rest of the housingstructure by suitable machine screws 593.

As shown in FIG. 46, the ball screw nut 580 has rotatably mountedtherethrough an elongated ball screw 581 which has the rear end thereofsupported in a ball screw support indicated by the numeral 582. The rearend of the ball screw 581 is rotatably mounted in a pair of suitablebearing means 583 which are carried in the support 582. The rear end ofthe ball screw 581 is drivably connected by a suitable flexible coupling586 to the output shaft 587 of an alternating current electric gearmotor, generally indicated by the numeral 588. The motor 588 is providedwith a disc brake 589. The motor 588 is secured by suitable machinescrews 594 to a motor mounting bracket 590. The motor bracket 590 issecured by suitable bolt and nut means 591. As shown in FIG. 45, thepallet changer 22 is provided with a pair of longitudinally spaced apartlimit switches 599 and 600 which are adapted to be engaged and operatedby the bracket 579 when the ball screw nut 580 reaches its retractedposition shown in FIGS. 45 and 46, and when it reaches its advancedposition shown by the broken line position 576a in FIG. 43.

It will be seen that the pallet changer 22 illustrated in FIG. 1 has asomewhat different transfer arm. The numeral 601 indicates a guide rodwhich is operatively connected to a carrier member 602. The carriermember is operatively connected to the aforedescribed ball screw nut 580for moving the carrier member 602 longitudinally of the housing 525. Theguide rod 601 slides in the slot 596 and then in the downwardly extendedslot 595 at the rear end of the slot 596 for moving the carrier member602 downwardly to detach the same from the locating tongue 521 on apallet. A transfer arm 603 is carried by the carrier member 602 and itis provided with the notch 604 for the reception of a locating tongue521 on a pallet.

A pair of pallets, as indicated by the numerals 18 and 19 in FIG. 1, areemployed when the machining center of the present invention is providedwith the optional pallet changer 22. For example, the first pallet 18would have a workpiece mounted thereon for machining by a tool 108,while the operator is simultaneously removing a finished workpiece fromthe second pallet 19 and then mounting a new workpiece thereon inpreparation for transferring the pallet 19 onto the work table assembly16. After the workpiece on the pallet 18 has been machined, the worktable assembly 16 is moved outwardly, or to the left as viewed in FIGS.4 and 39, on the "Z" axis, and during the last one inch of outwardtravel, the cam surface 506 (FIG. 39) on the lower end of the shaft 497engages the upwardly sloping cam surface 507 on the unlocking wedge orcam 504, and the clamp plate 477 is moved upwardly away from theclamping shoulders 495. Continued upward movement of the clamping plate477 lifts the pallet 18 upwardly so that the locating tongues 521 on thelocating plates 517 are moved upwardly above the locating plates 515.

It will be understood that the transfer arm 574 is positioned in theadvanced position, shown in FIG. 43 by the numeral 574a, before the worktable assembly 16 is moved into operative engagement with the unlockingcam 504. It will be seen that the locating plate 517 on the left side ofthe pallet 18, as viewed in FIGS. 39 and 41, has an extension portionthereon which extends sidewardly out beyond the pallet 18, and whichduring the last one inch outward travel of the work table assembly 16will be moved into the groove 575 in the transfer arm 574. When theoutward movement of the work table assembly 16 has been completed, andthe pallet 18 unlocked and raised upwardly from the base member 474, thedrive motor 588 for the ball screw 581 is then energized, and the ballscrew nut 580 will be moved from the advanced position indicated by thenumeral 580a in FIG. 46, back to the retracted position shown in FIG. 46by the numeral 580. The transfer arm 574, having previously been engagedwith the locating tongue 521 on the pallet 18, will pull the pallet 18off of the base member 474 onto the supporting guide plate 526 and intothe position indicated by FIG. 45 by the numeral 18a.

The drive motor 548 is next energized and the guide plate 526 is rotatedin a counterclockwise direction, as viewed in FIG. 46, to move thepallet 19 into the forward position of the pallet 18a, and the pallet18a into the rearward position of the pallet 19.

It will be seen that when the transfer arm 574 is moved to theretracted, solid line position shown in FIG. 45, it is moved downwardlydue to the action of the key 578 moving downwardly into the enlargedslot 595, so as to be clear of the locating lip 521a. The downwardmovement of the key 578 is possible because the ball screw nut 580 isrotatable about the ball screw 581, and its rotative position iscontrolled by the key 578 sliding in the slots 595 and 596. After theaforementioned shifting of the pallets 18 and 19, in order to bring thepallet 19 with the new workpiece into the forward position adjacent thefront end of the pallet changer 22, the ball screw motor 588 isenergized to drive the nut 580 and the transfer arm 574 to the left, asviewed in FIG. 45 and 46. The key 578 then is moved upwardly and intothe longitudinal slot 596, and during such action the transfer arm 574is raised up in order to bring the slot 575 into engagement with thelocating tongue extension 521 on the newly positioned pallet 19.Continued movement then slides the pallet 19 off of the guide plates 526and onto the base member 474. The work table assembly 16 is then movedinwardly on the "Z" axis ways, or to the right, as viewed in FIG. 39, soas to move the cam surface 506 on the shaft 497 to the right along thesloping cam surface 507, and to move the clamp plate 477 downwardly toclamp the new pallet 19 in place on the base member 474. It will be seenthat when the work table assembly 16 is moved to the right, as viewed inFIGS. 39 and 40, the extension of the left locating plate 517 on thepallet 19 will be moved to the right out of engagement with the groove575 on the transfer arm 574 to release the pallet 19 from the transferarm 574.

Operation

The machining center 10 made in accordance with the principles of thepresent invention may be controlled by any suitable computer numericalcontrol system as for example, a "NUMERA-TROL" positioning controlsystem available on the market from the Ex-Cell-O Corporation of Troy,Michigan. The last mentioned positioning system is programmedincrementally, (4) axis, accepting tab sequential data. It willaccommodate the positioning of all linear axes as well as 360 discretepositions of the rotary axis. It will accept and control all feed ratesand rapid traverse rates. It will control all spindle speed selectionsand directions, coolant On-Off situations, the entire cycle and desiredsequence of automatic tool changing, and other control factors.

The computer numerical control system is operatively mounted in thecontrol panel 20, and it includes a conventional tape reader 608 that isshown in FIG. 1. As shown in FIG. 6, the tape reader 608 is enclosed ina housing which is disposed on the outside wall of the panel 20, andaccordingly, it does not put any heat into the control panel 20. Asshown in FIG. 6, the lower wall 610 of the housing in which the tapereader 608 is mounted is provided with an opening 609 to permit the flowof cooling air to pass up through the housing 608 and out through anopening 611 formed through the upper end of the front housing wall 612.

U.S. Pat. No. 3,753,237 illustrates an electronic circuit for randomtool selection which may be employed for controlling the machiningcenter 10 of the present invention. The rotary switch 18 shown in thecircuit of said patent would be used to replace the function of theup-down counter provided by the two limit switches 347 and 349 shown inFIG. 22. The control circuit of U.S. Pat. No. 3,753,237 may be employedwith the present invention by having the two limit switches 347 and 349carry out the function of rotary switch 18 of said circuit. Anothercontrol circuit that may be employed with the present invention is thecontrol circuit disclosed in copending U.S. patent application, Ser. No.364,721, filed Aug. 14, l973, and entitled "Electronic Structure For AndMethod of Random Tool Selection." Patent application, Ser. No. 364,721is a continuation-in-part of the aforementioned U.S. Pat. No. 3,753,237.

FIG. 49 is a block diagram of an illustrative electronic circuit forselection of tools from the carousel 13. The limit switch 347 has itsoperating arm 348 positioned so as to be operated by the slots 357formed in the back face of the carousel wheel 296 (FIG. 22). The tools108 are always taken out of and put back into the same tool slot 358(FIG. 21) on the carousel 13. Accordingly, the limit switches 347 and349 can be set to an initial or zero reference point, as when tool slot#1 is in the tool exchange location indicated by the upper solid lineposition of the tool 104 in FIG. 48. The limit switch 347 is an inputcount limit switch, and the limit switch 349 is an input home or presetlimit switch. The preset limit switch 349 is only operated by one of theslots 357 on the back face of the carousel wheel 296, that is, the slot357 which would indicate that the tool slot #1 is at the toolinterchange position. The slot 357 that operates the switch 349 is 90°out of position from the tool interchange position, and it is longerthan the other slots 357. The other slots 357 are formed to a shorterlength so as not to operate the preset switch 349. The limit switches347 and 349 are positioned 90° counterclockwise from the toolinterchange position (FIG. 22). The master control unit is programmedrelative to the specific tool or each specific one of the twentyfourtool slot locations, and the tool carried therein.

The tool request data is entered via the tape reader 608 of a masterdata input keyboard. The tool request is then interfaced to the toolnumber memory 625 in the programmable interface control, generallyindicated by the numeral 623 in FIG. 49, and the computer memory 628.The tool request is channeled through the tape reader interface 621 andthe computer bus 619. The tool request is also interfaced to thecoincidence logic 626. The input from the counter limit switch 347 andthe preset limit switch 349 is entered via the input circuit 622 and itis channeled through the slow bus 630, and the bus input-outputinterface 629 to the computer bus 619, and to the tool at interchangecounter 627. The coincidence logic 626 compares the tool request numberwith the tool number at the interchange point which is calculated by thetool counter logic.

The tool counter logic is in two segments wherein one segment counts upand the other segment counts down. Whether the count is to be made up ordown is determined by the direction of rotation of the carousel 13. Thedirection of rotation of the carousel 13 is determined by the presenceor absence of the master code logic 624. If there is no coincidence whenthe coincidence logic 626 compares the tool request number with the toolat the interchange point, then the programmable interface control 623outputs a signal to rotate the carousel 13. If there is coincidence withthe coincidence logic 626 when compared with the tool request number,then the carousel motor 324 is stopped, since the carousel 13 is in theproper position with the desired tool at the tool interchange point. Ifthere is no coincidence, the direction of rotation of the carousel 13 isdetermined by an input function termed M-20 which will cause acounterclockwise rotation of the carousel 13, and said input is enteredfrom the control panel 615. As the carousel 13 is rotated, the counterlimit switch 347 counts up or down in binary code. The countertabulation goes into the tool logic of the tool counter 627. The toolcounter 627 can also be referenced by a manual request for tool number24 through the set up panel 617 which causes the carousel 13 to go in aclockwise direction, and the carousel to rotate through the homeposition, namely, the #1 tool slot position. When the carousel 13 goesthrough the home position, the home or preset limit switch 349 isoperated and the counter 627 is preset at 1, and the limit switch 347then starts counting and creates an electric pulse for each count whichis added to the preset 1 count on the tool counter 627. The countertabulation goes into the coincidence logic 626 and it is compared to theactual tool number that has previously been called up, and whencoincidence is reached, the carousel motor 324 is stopped with thecorrect tool at the interchange point. The rotation control signals forthe carousel motor 324 are channeled through the slow bus 630 and theoutput circuit 631 to the motor 324. The status display 616 include allof the lights on the front panel of the general control panel 20. Thecontrol panel structure 615 and the set up panel structure 617 is alsocarried on the general control panel 20. As each new tool number isentered, all the tool offsets for that tool are made active for use incutter path calculations.

The operation of transferring a previously used tool from the toolspindle 47 to the carousel 13, and a new tool from the carousel 13 tothe tool spindle 47, is carried out in the following manner. As shown inFIG. 48, a used tool in a tool chuck 104 would be raised upwardly fromthe broken line position 104a shown in FIG. 48 to the tool exchangelocation indicated by the solid line position 104 when the tool spindleslide assembly 12 is moved upwardly to move the tool spindle from thebroken line position 47a to the solid line position 47. The spindle 47is stopped at the tool exchange location in a predetermined angularposition, by the aforedescribed unlock wedge 248 which also unlocks thetool chuck 104. The upward movement of the spindle 47 also inserts thetool chuck 104 back into the same pot 358 that it was stored in the sameangular position as it was removed from the carousel 13. The carousel 13then withdraws the tool chuck 104 by moving outwardly from the solidline position shown in FIG. 48 to an advanced position 13a. As describedhereinbefore, the carousel 13 is then rotated in an appropriatedirection by the control means to bring the next programmed tool pot 358into the lowermost position or tool change position during the outwardtravel of the carousel 13. The carousel 13 is then retracted to thesolid line position shown in FIG. 48, and during the last portion ofsuch retraction movement, the next new tool chuck 104 which was broughtto the tool change position is inserted axially into the spindle 47,with the drive key 101 received in the keyway 99 in the new tool chuck104. The tool spindle slide assembly 12 is then moved downwardly and theunlock wedge 248 is moved in a counterclockwise direction to the brokenline position shown in FIG. 14a by means of the spring 265, to lock thenew tool chuck 104 in the spindle 47, and unlock the tool spindle 47 forrotation. The tool spindle 47 functions to withdraw the new tool fromthe tool carousel 13 as the spindle 47 moves downwardly to the brokenline position shown in FIG. 48 by the numeral 47a, where it is thenready for a cutting operation with the new tool on a workpiece. The toolexchange location may also be termed a tool change position.

Twenty-four tools can be stored in the rotary, high-speed carousel 13and adjacent tools can be changed in a total time of four seconds. Itwill be seen that all or a part of the total number of twenty-four toolscapable of being carried by carousel 13 can be used in a desiredsequence of cutting operations on a workpiece, and that the tools areautomatically transferred between the spindle 47 and the carousel 13 inthe aforedescribed manner.

The operation of the optional pallet changer has been describedhereinbefore in detail, and it will be understood that the operation ofthe pallet changer may be controlled by any suitable electric controlsystem and that the pallet change takes place automatically by itself,but that the operator must initiate the start of the cycle.

It will be seen that the machining center of the present inventioneliminates the need for hydraulic control units which are noisy anddirty and require constant changing of oil. The electric drive motorsemployed in the machining center of the present invention are identicaland interchangeable, and a suitable motor is available from the Getty'sManufacturing Company, Inc., of Racine, Wis., and sold under model#30-2130-A or Model #10-3140-A, and this type motor is also shown inU.S. Pat. No. 3,558,942.

The use of the electric drive motors connected directly to the ballscrews eliminates heat because of the fewer components required in thedriving apparatus for the various moving parts of the machining center.The direct connection of the drive motors to the ball screws eliminatessome of the friction and resultant heat normally involved in the priorart type linkage structure. The generating of less heat in operating themachining center provides for a resultant greater accuracy in machiningoperations. The direct current motors and ball screw assemblies employedalso provide for fast traverse and reversal of the various slidemembers. The employment of the mechanical means, including the unlockwedge 248 for radially locating the spindle 47 and for releasing thetool chuck 104 carried in the spindle 47, provides for an all mechanicaloperation which is positive and efficient in operation. Accordingly,this is advantageous since there is no need to bother with anyelectrical or hydraulic adjustments.

The collet means employed in the invention, with the collet fingers 117being of constant diameter throughout their length when the colletfingers 117 are in the inoperative position, provides a collet meanswhich is cheaper and easier to manufacture, long lived, and fast inoperation. Because of the structure of the collet arms 117, they have asmaller movement to go through, from the free state or inoperativeposition to the operative position, and accordingly, they are subject toless fatigue and provide longer collet life.

The construction of the chamfer teeth on the spline clutch gear orspline gear 182 provides for an efficient low friction gear drive meansfor the spindle 47. The novel structure employed in the collet unlockingapparatus is accomplished by the movement of the tool spindle slideassembly 12 on the "Y" axis without the need for any extra power meansfor operating such structure.

While it will be apparent that the preferred embodiments of theinvention herein disclosed are well calculated to fulfill the objectsabove stated, it will be appreciated that the invention is susceptibleto modification, variation and change.

What is claimed is:
 1. In a machine tool, the combination of:(a) a toolspindle slide assembly, including a tool spindle rotatable on a firstaxis and being operatively mounted for transverse movement along asecond axis perpendicular to said first axis of rotation of the toolspindle; (b) a rotary tool storage and tool changer means rotatablymounted on a third axis which is parallel to said first axis andperpendicular to said second axis, and provided with a plurality ofannularly disposed tool holding sockets rotatable in a plane transverseto said third axis and which are each adapted for releasably holding atool therein; (c) means for moving said tool spindle slide assemblyalong said second axis to align said tool spindle with one of said toolholding sockets, whereby said rotary tool storage and tool changer meanswill releasably grasp a tool supported in said tool spindle; (d) meansfor providing relative axial movement between the tool spindle and therotary tool storage and tool changer means in one direction for removingsaid tool from the tool spindle; (e) means for rotating the rotary toolstorage and tool changer means to position a selected tool holdingsocket in axial alignment with said tool spindle; and, (f) said meansfor providing relative axial movement between the tool spindle and therotary tool storage and tool changer means, also providing relativeaxial movement in the other direction for inserting another tool fromsaid selected holding socket into the tool spindle.
 2. a machine tool asdefined in claim 1, including:(a) means for releasably retaining a toolin the tool spindle.
 3. A machine tool as defined in claim 2,including(a) means for rotating said tool spindle.
 4. A machine tool asdefined in claim 2, including:(a) means for stopping said tool spindlein a predetermined angular position.
 5. A machine tool as defined inclaim 4, including:(a) means for radially locating said tool spindlepositively in a predetermined angular position when the spindle isstopped and for releasing said means for retaining a tool in the toolspindle.
 6. A machine tool as defined in claim 5, including:(a) meansfor effecting a driving relationship between the tool spindle and a toolmounted therein.
 7. A machine tool as defined in claim 1, including:(a)a column assembly; and, (b) said tool spindle slide assembly beingslidably mounted on said column assembly for movement along said secondaxis.
 8. A machine tool as defined in claim 7, wherein:(a) said toolspindle slide assembly includes a housing for movement along said secondaxis; and, (b) said means for providing relative movement between thetool spindle and the rotary tool storage and tool changer means alongsaid second axis includes a power drive means mounted on said columnassembly and drivably engageable with said tool spindle slide assemblyhousing.
 9. A machine tool as defined in claim 8, wherein said powerdrive means includes:(a) a ball screw assembly means having a ball screwoperatively connected to said tool spindle slide assembly housing; and,(b) electric motor drive means operatively connected to said ball screwassembly means.
 10. A machine tool as defined in claim 9, wherein:(a)said electric motor drive means is directly connected to the ball screwof said ball screw assembly means.
 11. A machine tool as defined inclaim 2, wherein said means for releasably retaining a tool in the toolspindle, includes:(a) a collet means movingly mounted in said toolspindle, for movement in one direction for retaining a tool in the toolspindle, and for movement in the other direction for releasing the tool;(b) a draw bar movably mounted in said tool spindle and operativelyconnected to said collet means for moving said collet means; and, (c)spring means operatively mounted in said spindle for moving said drawbar in said one direction for retaining a tool in the tool spindle. 12.A machine tool as defined in claim 11, wherein said collet meansincludes:(a) a cylindrical collet body attached to said draw bar and aplurality of elongated spring fingers which are each provided with a camhead for gripping engagement with a tool in the tool spindle when thecollet means is moved in said one direction, and wherein the outersurfaces of the spring finger are arcuately shaped and form acylindrical periphery which is continuous and parallel with the circularsurface of the collet body when the cam fingers are in a free state, andwherein the cam heads are moved radially inward from said free stateposition into gripping engagement with a tool in the tool spindle whenthe collet means is moved in said one direction.
 13. A machine tool asdefined in claim 12, including:(a) means for radially locating said toolspindle in a predetermined angular position when the spindle is stopped,and for releasing said means for retaining a tool in the tool spindle.14. A machine tool as defined in claim 13, wherein:(a) said means forradially locating said tool spindle and for releasing said means forretaining a tool in the tool spindle includes a mechanical means.
 15. Amachine tool as defined in claim 14, wherein said mechanical meansincludes:(a) a pivotal wedge means movable between an inoperativeposition and an operative position; (b) means for biasing said wedgemeans into an inoperative position; and, (c) means for pivoting saidwedge means into an operative position in engagement with said toolspindle and draw bar, for radially locating the tool spindle, and formoving the draw bar in said other direction for releasing a tool in thetool spindle.
 16. A machine tool as defined in claim 15, wherein:(a)said means for biasing said wedge means into an inoperative positionincludes a spring means.
 17. A machine tool as defined in claim 16,wherein:(a) said wedge means is pivotally mounted on said tool spindleslide assembly; and, (b) said means for pivoting the wedge means intothe operative position includes a stop means engageable by said wedgemeans when the tool spindle slide assembly is moved in said otherdirection for returning a tool to a selected tool holding socket in therotary tool storage and tool changer means.
 18. A machine tool asdefined in claim 17, wherein:(a) said tool spindle is provided with slotmeans on the rear end thereof in which the wedge means is slidablyreceived when the wedge means is moved to the operative position forradially locating the tool spindle.
 19. A machine tool as defined inclaim 3, wherein:(a) said tool spindle slide assembly includes a housingfor movement along said second axis; and, (b) said means for rotatingsaid tool spindle includes a drive gear means carried in said housingand connected to said spindle for rotating the spindle, and a powerdrive means carried on said housing and drivably connected to said drivegear means.
 20. A machine tool as defined in claim 19, wherein saiddrive gear means includes:(a) a low speed gear train; (b) a high speedgear train; (c) a gear shaft drivably connected to said power drivemeans; and, (d) clutch means for selectively connecting the gear shaftto the low speed gear train or the high speed gear train.
 21. A machinetool as defined in claim 20, wherein said clutch means includes:(a) adriven clutch gear slidably mounted om said gear shaft for movementbetween a first position in driving engagement with said low speed geartrain, and a second position in driving engagement with said high speedgear train; and, (b) means for moving said driven clutch gear betweensaid first and second positions.
 22. A machine tool as defined in claim21, wherein said means for moving said driven clutch gear includes:(a) aspring means for moving said driven clutch gear to said first position;and, (b) a fluid motor means for moving said driven clutch gear to saidsecond position.
 23. A machine tool as defined in claim 22, wherein:(a)said power drive means includes an electric motor drive means.
 24. Amachine tool as defined in claim 23, wherein:(a) said electric motordrive means includes an output shaft directly connected to said clutchgear shaft.
 25. A machine tool as defined in claim 21, wherein saidclutch gear includes:(a) a pinion gear having a first set of spline typegear teeth for engagement with the low speed gear train, and a laterallyspaced second set of spline type gear teeth for engagement with the highspeed gear train.
 26. A machine tool as defined in claim 25, wherein:(a)each of the spline type gear teeth is provided with a chamfer on eachside at the outer end thereof, and a chamfer on the outer peripheralsurface at the outer end thereof.
 27. A machine tool as defined in claim20, including:(a) means for stopping said tool spindle in apredetermined angular position.
 28. A machine tool as defined in claim27, wherein:(a) said means for stopping said tool spindle in apredetermined angular position includes a position sensing means.
 29. Amachine tool as defined in claim 28, wherein said position sensing meansincludes:(a) a proximity switch mounted on said tool spindle slideassembly housing; and, (b) a magnet mounted on one of the gears of saiddrive gear means for alignment with said proximity switch for stoppingthe tool spindle in a predetermined angular position.
 30. A machine toolas defined in claim 7, wherein said means for providing relativemovement between the tool spindle and the rotary tool storage and toolchanger means includes:(a) means mounted on said column assembly forsupporting said rotary tool storage and tool changer means for axialmovement toward said column assembly for inserting a tool in the toolspindle, and for axial movement away from the column assembly forremoving a tool from the tool spindle; and, (b) power drive means formoving said rotary tool storage and tool changer means through saidaxial movements.
 31. A machine tool as defined in claim 30, wherein saidmeans for rotating the rotary tool storage and tool changer meansincludes:(a) means carried on said axial movement support means forrotatable support of said rotary tool storage and tool changer means forbi-directional rotation; and, (b) power drive means carried on saidaxial movement support means and drivably connected to said rotatablesupport means.
 32. A machine tool as defined in claim 31, wherein:(a)said rotary tool storage and tool changer means includes a wheeldisposed for rotation in a plane perpendicular to the axis of rotationof the rotary tool storage and tool changer means; and, (b) saidplurality of tool holding sockets are formed in the periphery of saidwheel.
 33. A machine tool as defined in claim 32, including:(a) meansfor releasably retaining a tool in each of said tool holding sockets ina predetermined radial position; and, (b) means in each tool holdingsocket for axially locating of a tool held therein.
 34. A machine toolas defined in claim 33, including:(a) means for sensing the rotaryposition of the tool storage and tool changer wheel.
 35. A machine toolas defined in claim 34, wherein said means for sensing the rotaryposition of the tool storage and tool changer wheel includes:(a) a firstswitch means operable when said wheel is rotated in one direction; and,(b) a second switch means operable when said wheel is rotated in theother direction.
 36. A machine tool as defined in claim 33, wherein saidreleasable retaining means for retaining a tool in each of said toolholding sockets comprises:(a) spring clip means.
 37. A machine tool asdefined in claim 33, wherein said axially locating means comprises:(a) aradially disposed locating finger in each socket which is operablyengageable with a tool in the socket.
 38. A machine tool as defined inclaim 31, wherein said power drive means comprises:(a) an electric motordrive means; and, (b) a gear drive means drivably connecting said motordrive means to the rotatable support means.
 39. A machine tool asdefined in claim 30, wherein said axial movement mounting meansincludes:(a) a support housing mounted on said column assembly; and, (b)a carrier shaft slidably supported on said support housing.
 40. Amachine tool as defined in claim 39, wherein said power drive meanscomprises:(a) a fluid cylinder carried on said column assembly andhaving a cylinder rod connected to said carrier shaft.
 41. A machinetool as defined in claim 7, including:(a) an X-axis ways base adjacentthe column assembly; (b) a saddle slide assembly slidably mounted onsaid X-axis ways and carrying Z-axis ways; (c) a power drive meansmounted on said X-axis ways base and engageable with said saddle slideassembly for moving the same along the X-axis ways; (d) a work tableslide assembly slidably mounted on said Z-axis ways; (e) a power drivemeans mounted on said saddle slide assembly and engageable with saidwork table slide assembly for moving the same along said Z-axis ways;(f) a work table rotatably mounted on said work table slide assembly;and, (g) a power drive means for rotating said work table.
 42. A machinetool as defined in claim 41, wherein:(a) said power drive means formoving said saddle slide assembly and said power drive means for movingsaid work table slide assembly, each comprises an electric drive motormeans and a ball screw assembly means.
 43. A machine tool as defined inclaim 42, wherein:(a) each of said electric drive motor means isdirectly connected to the ball screw of one of said ball screw assemblymeans.
 44. A machine tool as defined in claim 41, wherein:(a) said powerdrive means for rotating said work table comprises an electric drivemotor means, and a drive worm and gear means.
 45. A machine tool asdefined in claim 44, wherein:(a) said drive worm is operatively mountedon a drive shaft; and, p1 (b) said electric drive motor means isdirectly connected to said drive shaft.